Table 18.21-2. The 2010 American College of Rheumatology/European League Against Rheumatism rheumatoid arthritis classification criteria

Target population (who should be tested)

Patients with:

1) ≥1 joint with definite clinical synovitis (swelling)

2) Synovitis not better explained by another diseasea

The criteria are aimed at classification of newly presenting patients. In addition, patients with erosive disease typical of RAb or with long-standing disease, including those whose disease is inactive (with or without treatment), who based on retrospectively available data had previously fulfilled the 2010 criteria, should be classified as having RA.

Classification criteria for RA (score-based algorithm: add score of categories A-D; a score ≥6/10 is needed to classify a patient as having RA)c

A. Joint involvementd


1 large jointe


2-10 large joints


1-3 small jointsf (with or without involvement of large joints)


4-10 small joints (with or without involvement of large joints)


>10 jointsg (including ≥1 small joint)


B. Serology (≥1 test result is needed for classification)h


Negative RF and negative ACPAs


Low-positive RF or low-positive ACPAs


High-positive RF or high-positive ACPAs


C. Acute-phase reactants (≥1 test result is needed for classification)


Normal CRP and normal ESR


Abnormal CRP or abnormal ESR


D. Duration of symptomsi


<6 weeks


≥6 weeks


a Differential diagnosis may include conditions such as SLE, psoriatic arthritis, and gout.

b Erosions (defined as disruptions of the bone cortex) revealed on radiographs of hands and feet in ≥3 individual joints among proximal interphalangeal joints, metacarpophalangeal joints, wrist joints (counted as 1 joint), and metatarsophalangeal joints.

c Patients with a score <6/10 are not classifiable as having RA, however their status can be reassessed and the criteria may be fulfilled cumulatively over time.

d Joint involvement refers to any swollen or tender joint on examination, which may be confirmed by imaging evidence of synovitis. Distal interphalangeal joints, first carpometacarpal joints, and first metatarsophalangeal joints are excluded from assessment (these are typically involved in osteoarthritis).

e Large joints: Shoulders, elbows, hips, knees, and ankles.

f Small joints: Metacarpophalangeal joints, proximal interphalangeal joints, second through fifth metatarsophalangeal joints, thumb interphalangeal joints, and wrists.

g In this category ≥1 of the involved joints must be a small joint. Other joints can include any combination of large and additional small joints as well as other joints not specifically listed elsewhere (eg, temporomandibular, acromioclavicular, sternoclavicular).

h Negative results refer to international unit values that are less than or equal to the ULN for the laboratory and assay. Low-positive results refer to international unit values that are higher than the ULN but 3 times the ULN for the laboratory and assay. High-positive results refer to international unit values that are 3 times the ULN for the laboratory and assay.

i Duration of symptoms refers to the patient’s self-report of the duration of signs or symptoms of synovitis (eg, pain, swelling, tenderness) of joints that are clinically involved at the time of assessment, regardless of treatment status.

Source: Ann Rheum Dis. 2010;69(9):1580-8.

ACPA, anti-citrullinated peptide antibody; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; RA, rheumatoid arthritis; RF, rheumatoid factor; SLE, systemic lupus erythematosus; ULN, upper limit of normal.